Cutting element and method of forming thereof

ABSTRACT

A cutting element comprising a substrate having an upper surface, a rear surface spaced apart from the upper surface, and a side surface connected to the rear surface and upper surface. The cutting element further includes a superabrasive layer comprising a rear surface, an upper surface, and a side surface connected to and extending between the rear surface and upper surface, wherein the rear surface of the superabrasive layer overlies the upper surface of the substrate. The cutting element is also formed to include a jacket overlying the side surface of the substrate and abutting a portion of the rear surface of the superabrasive layer, wherein the jacket comprises a flange extending along a portion of the side surface of the superabrasive layer.

BACKGROUND

1. Field of the Disclosure

The following disclosure is directed to cutting elements for use in drill bits and/or milling bits, and particularly cutting elements incorporating a cutting body and a jacket.

2. Description of the Related Art

In the past, rotary drill bits have incorporated cutting elements employing superabrasive materials. Within the industry there has been widespread use of synthetic diamond cutters using polycrystalline diamond compacts, otherwise termed “PDC” cutters. Such PDC cutters may be self supported, otherwise a monolithic object made of the desired material, or incorporate a polycrystalline diamond layer or “table” on a substrate made of a hard metal material suitable for supporting the diamond layer.

However, PDC cutter designs continue to face obstacles. For example, mechanical strains are commonplace given the significant loading on the cutters, and as such, delamination and fracture of the cutters, particularly of the diamond table, can occur given the extreme loading and temperatures generated during drilling operations. Furthermore, failure of the cutters due to temperature concerns can go beyond the existence of simply encountering high temperatures, but the effects of heating and cooling on the cutters and the resultant failure of the cutters due to differences in thermal expansion coefficient and thermal conductivity of materials within the cutter.

Various configurations of cutters have been used to mitigate the effects of mechanical strain and temperature-induced wear characteristics. However, significant shortcomings are still exhibited by conventional cutters.

SUMMARY

According to one aspect, a cutting element includes a substrate having an upper surface, a rear surface spaced apart from the upper surface, and a side surface connected to the rear surface and upper surface. The cutting element further includes a superabrasive layer comprising a rear surface, an upper surface, and a side surface connected to and extending between the rear surface and upper surface, wherein the rear surface of the superabrasive layer overlies the upper surface of the substrate. A jacket can overlay the side surface of the substrate, abutting a portion of the rear surface of the superabrasive layer, wherein the jacket comprises a flange extending along a portion of the side surface of the superabrasive layer.

In accordance with another aspect, a cutting element includes a cutter body comprising a substrate having an upper surface, a rear surface spaced apart from the upper surface, and a side surface connected to the rear surface and upper surface. The cutting element also employs a superabrasive layer comprising a rear surface overlying the upper surface of the substrate at a substrate/superabrasive layer interface, and a jacket comprising an erosion-resistant material overlying a periphery of the substrate/superabrasive layer interface at a side surface of the substrate, wherein the jacket extends for a fraction of a total length of the cutter body.

In yet another aspect, a cutting element includes a substrate having an upper surface, a superabrasive layer comprising a rear surface overlying the upper surface of the substrate at a substrate/superabrasive layer interface, and a jacket overlying a periphery of the substrate/superabrasive layer interface, wherein the jacket comprises a coating including an erosion-resistant material.

According to still another aspect, a cutting element includes a substrate having an upper surface, a rear surface spaced apart from the upper surface, and a side surface connected to the rear surface and upper surface. The cutting element incorporates a superabrasive layer comprising a rear surface, an upper surface, and a side surface connected to and extending between the rear surface and upper surface, wherein the rear surface of the superabrasive layer overlies the upper surface of the substrate. Additionally, the cutting element includes a jacket abutting a portion of the rear surface of the superabrasive layer, wherein the jacket comprises an axially varying composition.

In accordance with another aspect, a cutting element includes a cutter body comprising a substrate having an upper surface, a rear surface spaced apart from the upper surface, and a side surface connected to the rear surface and upper surface. The cutting element has a superabrasive layer comprising a rear surface, an upper surface, and a side surface connected to and extending between the rear surface and upper surface, wherein the rear surface of the superabrasive layer overlies the upper surface of the substrate. Also, the cutting element includes a jacket releasably attached to the cutter body.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be better understood, and its numerous features and advantages made apparent to those skilled in the art by referencing the accompanying drawings.

FIG. 1 includes an illustration of a subterranean drilling operation.

FIG. 2 includes an illustration of a drill bit in accordance with an embodiment.

FIGS. 3A-3B include a cross-sectional illustrations and a perspective view illustration of a cutter element in accordance with an embodiment.

FIGS. 4A-4D includes cross-sectional illustrations of cutting elements in accordance with embodiments.

FIGS. 5A-5C include cross-sectional illustrations of cutting elements in accordance with embodiments.

FIGS. 6A-6B include cross-sectional illustrations of cutting elements in accordance with embodiments.

FIG. 7 includes a cross-sectional illustration of a cutting element in accordance with an embodiment.

FIGS. 8A-8B include cross-sectional illustrations of cutting elements in accordance with embodiments.

FIGS. 9A-9E include cross-sectional illustrations and perspective view illustrations of cutting elements in accordance with embodiments.

FIGS. 10A-10C include cross-sectional illustrations of cutting elements in accordance with embodiments.

FIGS. 11A-11C include cross-sectional illustrations of cutting elements in accordance with embodiments.

The use of the same reference symbols in different drawings indicates similar or identical items.

DETAILED DESCRIPTION

The following is directed to earth boring drilling bits and/or milling bits, and more particularly, cutting elements used in such bits. The following describes cutting elements and methods of forming such elements such that they may be incorporated within drilling and/or milling bits. The terms “bit”, “drill bit”, and “matrix drill bit” may be used in this application to refer to “rotary drag bits”, “drag bits”, “fixed cutter drill bits”, “mill- and drill-bits”, “milling bits” or any bits incorporating the teachings of the present disclosure. As will be appreciated, such drill bits may be used to form well bores or boreholes in subterranean formations as well as mill through casings or other objects within a borehole.

An example of a drilling system for drilling such well bores in earth formations is illustrated in FIG. 1. In particular, FIG. 1 illustrates a drilling system including a drilling rig 101 at the surface, serving as a station for workers to operate a drill string 103. The drill string 103 defines a well bore 105 extending into the earth and can include a series of drill pipes 100 and 103 that are coupled together via joints 104 facilitating extension of the drill string 103 for depths into the well bore 105. The drill string 103 may include additional components, such as tool joints, a kelly, kelly cocks, a kelly saver sub, blowout preventers, safety valves, and other components known in the art.

Moreover, the drill string can be coupled to a bottom hole assembly 107 (BHA) including a drill bit 109 used to penetrate earth formations and extend the depth of the well bore 105. The BHA 107 may further include one or more drill collars, stabilizers, a downhole motor, MWD tools, LWD tools, jars, accelerators, push and pull directional drilling tools, point stab tools, shock absorbers, bent subs, pup joints, reamers, valves, and other components. A fluid reservoir 111 is also present at the surface that holds an amount of liquid that can be delivered to the drill string 103, and particularly the drill bit 109, via pipes 113, to facilitate the drilling procedure.

FIG. 2 includes a perspective view of a fixed cutter drill bit according to an embodiment. The fixed cutter drill bit 200 has a bit body 213 that can be connected to a shank portion 214 via a weld. The shank portion 214 includes a threaded portion 215 for connection of the drill bit 200 to other components of the BHA. The drill bit body 213 can further include a breaker slot 221 extending laterally along the circumference of the drill bit body 213 to aid coupling and decoupling of the drill bit 200 to other components.

The drill bit 200 includes a crown portion 222 coupled to the drill bit body 213. As will be appreciated, the crown portion 222 can be integrally formed with the drill bit body 213 such that they are a single, monolithic piece. The crown portion 222 can include gage pads 224 situated along the sides of protrusions or blades 217 that extend radially from the crown portion 222. Each of the blades 217 extend from the crown portion 222 and include a plurality of cutting elements 219 bonded to the blades 217 for cutting, scraping, and shearing through earth formations when the drill bit 200 is rotated during drilling. The cutting elements 219 may be polycrystalline diamond compacts (PDC) or any of the cutting elements described herein. Coatings or hardfacings may be applied to other portions of the bit body 213 or crown portion 222 to reduce wear and increase the life of the drill bit 200.

The crown portion 222 can further include junk slots 227 or channels formed between the blades 217 that facilitate fluid flow and removal of cuttings and debris from the well bore. Notably, the junk slots 227 can further include openings 223 for passages extending through the interior of the crown portion 222 and bit body 213 for communication of drilling fluid through the drill bit 200. The openings 223 can be positioned at exterior surfaces of the crown portion 222 at various angles for dynamic fluid flow conditions and effective removal of debris from the cutting region during drilling.

FIGS. 3A-3B include a cross-sectional illustration and a perspective view illustration of a cutting element in accordance with an embodiment. In particular, FIG. 3A includes a cross-sectional illustration of a cutting element 300 employing a cutter body 350 and a jacket 303 extending around a portion of the cutter body 350 in accordance with an embodiment. The cutter body 350 can include a substrate 301 having an upper surface 307 extending transversely to the longitudinal axis 308, a rear surface 396 parallel to the upper surface 307 and extending transversely to the longitudinal axis 308, and a side surface 305 extending between the upper surface 307 and rear surface 396 and extending parallel to the longitudinal axis 308. The substrate 301 can provide support for forming a superabrasive layer 302 thereon.

In reference to the substrate 301, the substrate can be made of a material suitable for withstanding drilling applications. For example, the substrate 301 can employ a material having a Mohs hardness of at least about 8, or at least about 8.5, at least about 9.0, or even at least about 9.5. The substrate 301 can be formed of a carbide, nitride, oxide, boride, carbon-based material, and a combination thereof. Particular metals or metal alloy materials may be incorporated in the substrate 301, such that the substrate can be made of a cermet. In some instances, the substrate 301 can be made of a cemented material, such as a cemented carbide. Some suitable cemented carbides can include metal carbides, and particularly cemented tungsten carbide. According to one embodiment, the substrate 301 consists essentially of tungsten carbide.

The substrate 301 can have a shape comprising an elongated portion defining a length extending along a longitudinal axis 308. In certain designs, the side surface 305 of the substrate 301 can have an arcuate shape defining a circumference extending at a radius around the longitudinal axis 308. For instance, the substrate 301 may have a cylindrical shape (e.g., a right cylinder), such that it has a circular cross-sectional contour as viewed in cross-section to the longitudinal axis 308. It will be appreciated that alternative shapes for the substrate 301 and cutting elements herein are possible, including polygonal cross-sectional contours (e.g., rectangular, trapezoidal, pentagonal, triangular, etc.), elliptical cross-sectional contours, hemispherical cross-sectional contours, and the like. Accordingly, it will be further appreciated that reference herein to a circumference with regard to the cutting element or any of its components is reference to a dimension extending around the periphery of the identified article. As such, for designs of cutters having non-circular cross-sectional contours, reference to a circumference herein will be understood to be a reference to a dimension of the periphery.

According to certain embodiments, the substrate 301 can be formed to have a chamfered surface 322 that can extend between the rear surface 396 and the side surface 305 of the substrate 301. The chamfered surface 322 can extend at an angle to the longitudinal axis 308 and can have various lengths and angles.

The cutter body 350 can include a superabrasive layer 302 overlying the upper surface 307 of the substrate 301. In particular, the superabrasive layer 302 can be in direct contact with (i.e., abutting) the upper surface 307, and more particularly, bonded directly to the upper surface 307 of the substrate 301. In certain designs, the superabrasive layer 302 can be formed such that it has a rear surface 316 forming an interface with the upper surface 307 of the substrate 301 extending transversely to the longitudinal axis 308. The superabrasive layer 302 can have an upper surface 309 parallel to the rear surface 316 that extends transversely to the longitudinal axis 308. A side surface 306 of the substrate can extend between the rear surface 316 and upper surface 309 parallel to the longitudinal axis 308 of the cutter body 350.

The superabrasive layer 302 can include superabrasive materials such as diamond, boron nitride (e.g, cubic boron nitride), certain carbon-based materials, and a combination thereof. The superabrasive layer can include a polycrystalline material. In fact, according to certain designs, the superabrasive layer 302 can consist essentially of polycrystalline diamond. With reference to those embodiments using polycrystalline diamond, the superabrasive layer 302 can be made of various types of diamond including thermally-stable polycrystalline diamond, which generally contain a lesser amount of catalyst material (e.g., cobalt) than other diamond materials, making the material stable at higher temperatures. In other applications, the superabrasive layer 302 can be formed such that it consists essentially of polycrystalline cubic boron nitride.

In some embodiments, the superabrasive layer 302 has a thickness 332 (t_(sal)) measured in a direction substantially parallel to the longitudinal axis 308 of the cutter body 350. The superabrasive layer 302 can have a volume and average thickness 332 (t_(sal)) suitable for operating in combination with other components (e.g., a jacket 303) for improved performance. Generally, the superabrasive layer can have a thickness 332 (t_(sal)) of at least about 0.5 mm, such as at least about 1 mm, at least about 2 mm, at least about 3 mm or even at least about 4 mm. In certain exemplary designs, the superabrasive layer has a thickness within a range between about 0.5 mm and about 5 mm.

The superabrasive layer 302 can employ a chamfered surface 345 abutting the upper surface 309. The chamfered surface 345 can improve the cutting performance of the cutting element 300. In particular, the chamfered surface 345 can extend between the upper surface 309 and side surface 306 of the superabrasive layer 302. As illustrated, the chamfered surface 345 can extend at an angle to the upper surface 309 and the side surface 306, and more particularly, at an angle to the longitudinal axis 308 of the cutter body 350. Various angles and lengths may be employed on the chamfered surface 345 depending upon the intended application. As will be appreciated, the chamfered surface 345 may extend around the entire periphery of the superabrasive layer 302, such that it is in the shape of an annulus.

Still, in certain designs, the chamfered surface 345 may be segmented, such that it is made of discrete portions, wherein each portion extends for a distance less than the entire periphery (i.e., less than 360°) around the cutter body 350. Moreover, in certain instances, it may be desirable to use a radiused edge as opposed to a chamfered surface. A radiused edge can have a curvature or arcuate shape that can define a radius. As such, it will be appreciated that references herein to chamfered surfaces will be understood to also include radiused edge configurations. Furthermore, it will be appreciated that the chamfered surface can be made of multiple surfaces, such that the chamfered surface comprises at least two or more surfaces, which can be angled relative to each other and the other surfaces of the superabrasive layer 302.

As further illustrated in FIG. 3A, the cutting element 300 can include a jacket 303 extending around a portion of the side surface 306 of the superabrasive layer 302 and the side surface 305 of the substrate 301. As illustrated, the jacket 303 comprises an inner surface 310, which can extend substantially parallel to the longitudinal axis 308, and an outer surface 311, opposite the inner surface 310, which can extend substantially parallel to the longitudinal axis 308. Additionally, the jacket 303 can have an upper surface 346 and a rear surface 314, each of which can extend between the inner surface 310 and outer surface 311, parallel to each other and in a direction substantially perpendicular to the longitudinal axis 308 of the cutter body 350.

As further illustrated, the jacket 303 can be formed to have a chamfered surface 347 that can extend between the upper surface 346 and the outer surface 311. The chamfered surface 347 can improve the cutting behavior, abrasion resistance, and erosion resistance of the cutting element 300. The chamfered surface 347 can extend at an angle to the upper surface 346, the outer surface 311 and the longitudinal axis 308 of the cutter body 350.

The jacket 303 can be formed to include a chamfered surface 323 at the rear of the cutter body 350. The chamfered surface 323 can provide coverage of the chamfered surface 322 of the substrate 301 to improve erosion resistance. In particular embodiments, the chamfered surface 323 can extend between the rear surface 314 and the outer surface 311 of the jacket 303, and more particularly, at an angle to the rear surface 314, outer surface 311, and longitudinal axis 308 of the cutter body 350.

The jacket 303 can be formed such that it extends peripherally (e.g., circumferentially) along the side surface 306 of the superabrasive layer 302 and the side surface 305 of the substrate 301. The amount of peripheral coverage of the jacket can be measured in degrees of coverage based on a central angle measured perpendicular to the longitudinal axis 308 and centered at the center of the cutter body 350 defined by the longitudinal axis 308. According to some designs, the jacket can extend through the entire periphery (i.e., 360° of coverage) of the cutter body 350. That is, the jacket 303 is a single, monolithic piece extending around the entire circumference of the side surface 306 of the superabrasive layer 302 and the side surface 305 of the substrate 301.

Alternatively, some cutting elements can incorporate a jacket 303 formed of discrete jacket portions, wherein each discrete jacket portion extends through a fraction of the total peripheral distance of the cutter body 350. For example, a jacket portion can extend through not greater than 270°, such as not greater than 180°, such as not greater than 90°, or even not greater than 45° of the total peripheral distance of the cutter body 350. The discrete jacket portions can be mechanically attached to each other, such as in an interlocking arrangement, through overlapping lips, grooved connections, and the like. In other designs, the discrete jacket portions may be bonded to each other, such as through the use of a brazing composition.

The inner surface 310 defines a central opening wherein the cutter body 350 can be disposed. In particular, the jacket 303 can be formed such that the inner surface 310 is in direct contact (i.e., abutting) with the side surface 306 of the superabrasive layer 302. In particular designs, the jacket 303 is formed such that the inner surface 310 is directly bonded to the side surface 306 of the superabrasive layer 302. Likewise, the jacket 303 can be formed such that the inner surface 310 is directly contacting the side surface 305 of the substrate 301, and in particular, can be directly bonded to the side surface 305 of the substrate 301. Direct bonding between the jacket 303 and the side surface 305 of the substrate 301 may be achieved using a single-step forming process, such as an HPHT process, which is provided in more detail herein.

The jacket 303 can extend along certain portions of the length (i.e., measured parallel to the longitudinal axis 308) of the cutter body 350. For example, the jacket 303 can extend along at least 50% of the entire length of the cutter body 350 from the rear surface 396 of the substrate 301 to the upper surface 309 of the superabrasive layer 302. In other embodiments, the jacket 303 is designed to extend over a greater portion of the total length of the cutter body 350, such as at least about 60%, at least about 75%, at least about 80%, and even at least about 90%. According to one particular embodiment, the jacket 303 is formed to extend substantially along the entire length of the cutter body 350, wherein the front surface 346 of the jacket 303 terminates at the edge between the chamfered surface 345 and the side surface 306 of the superabrasive layer 302. It will be appreciated that certain embodiments may utilize a jacket 303 extending for a fraction of the full length of the substrate 301 along the longitudinal axis 308, which can refer to a collar as described in more detail herein.

In particular designs, the jacket 303 can be formed to have a flange 348 that extends along a portion of the superabrasive layer 302. That is, the flange 348 can extend along and overlie at least a portion of the side surface 306 of the superabrasive layer 302. In particular, the flange 348 can have an inner surface 318 that extends along the side surface 306 in the direction of the longitudinal axis 308, and therein overlies the side surface 306. Notably, the inner surface 318 can be abutting the side surface 306 of the superabrasive layer 302. The inner surface 318 of the flange 348 can extend for a fraction of the entire thickness (as measured in the same direction as the thickness 332) of the side surface 306. In still other designs, the inner surface 318 of the flange 348 can extend for the entire thickness of the side surface 306 as measured between the rear surface 316 and the edge of the chamfered surface 345 joined to the side surface 306.

Additionally, the jacket 303 can be formed such that at least a portion of the jacket 303 can be abutting the rear surface 316 of the superabrasive layer 302. In some designs, such as illustrated in FIG. 3A, the jacket 303 can be formed to have a surface 313 that is abutting a portion of the rear surface 316 of the superabrasive layer 302. Notably, the surface 313 of the jacket 303 can extend at an angle to the longitudinal axis 308, such as a substantially perpendicular to the longitudinal axis 308, such that it complements the contours of the portion of the rear surface 316 of the superabrasive layer 302 that the surface 313 abuts. Moreover, the surface 313 can be bonded to the rear surface 316 of the superabrasive layer 302.

In accordance with embodiments herein, the cutting element 300 is formed such that the jacket 303 can exert a radially compressive force and an axial force on the superabrasive layer 302. Accordingly, the forces exerted by the jacket 303 on the superabrasive layer 302 are provided in a manner such that a significant portion of the force, or even a majority of the force, or even entirely all of the force applied by the jacket 303 is a radially compressive force acting in a direction substantially perpendicular to the longitudinal axis 308 of the cutter body 350 at the side surface 306 of the superabrasive layer 302. Such forces can improve the cutting capabilities of the cutting element 300.

The jacket 303 can be formed such that is has an average thickness 333 (t_(s)) as measured in a direction perpendicular to the longitudinal axis 308 between the inner surface 310 and the outer surface 311 of the jacket 303 that is not greater than about 5 mm. According to other embodiments, the jacket 303 can have an average thickness 333 (t_(s)) that is at least about 0.1 mm, such as at least about 0.5 mm, at least about 1 mm, at least about 2 mm, or even at least about 3 mm. Still, certain embodiments utilize a jacket 303 having an average thickness 333 (t_(s)) that is not greater than about 5 mm, on the order of not greater than about 4 mm, such that it is not greater than about 3 mm, or even not greater than about 2 mm. More particular designs may utilize an average jacket thickness 333 (t_(s)) within a range between about 0.1 mm and about 5 mm, such as between about 1 mm and about 4 mm, such as between about 1 mm and about 3 mm, or even between about 2 mm and about 3 mm.

Moreover, the flange 348 of the jacket 303 can be formed such that it has an average thickness 336 (t_(jf)) as measured between the surface 318 of the jacket 303 and the outer surface 311 of the jacket in a direction perpendicular to the longitudinal axis 308. Notably, the average thickness 336 of the flange 348 can be different than the average thickness 333 of the jacket 303 at a position along the jacket 303 overlying the substrate 301. In particular, the average thickness 336 of the flange 348 can be less than the average thickness of the jacket 303 at a position overlying the substrate 301.

The cutting element 350 including the jacket 303 may be formed to have a particular outer diameter 334 (OD_(s)). In particular embodiments, the jacket 303 can be formed to have an outer diameter 334 (OD_(s)) within a range between 8 mm to about 40 mm, or even between about 8 mm and about 30 mm.

Certain cutting elements utilize a jacket 303 that can include erosion-resistant materials, corrosion-resistant materials, and a combination thereof. The jacket 303 can be formed of a material including an inorganic material, organic material, and a combination thereof. The material of the jacket 303 can be a polycrystalline material, an amorphous material, and a combination thereof. The jacket 303 can be made of certain inorganic materials, such as a ceramic, cermet, metal or metal alloy material. Some suitable metal or metal alloy materials can include transition metal elements. Examples, of some suitable metal elements for use in the jacket 303 can include titanium, chromium, nickel, tungsten, cobalt, iron, molybdenum, vanadium, and a combination thereof.

In certain embodiments, it may be suitable to form a jacket 303 comprising a super-alloy material, which is a metal or metal alloy having superior hardness and refractoriness, and which typically incorporates metal elements such as tungsten, chromium, cobalt, iron, and nickel. Some such suitable super-alloys can include nickel-based materials, cobalt-based materials, chromium-based material, and/or cobalt-chromium-based materials. In fact, super-alloy compositions include a majority amount of nickel, chromium, and/or cobalt (depending upon the precise composition) and may further include minor amounts of other alloying metal elements, such as molybdenum, tungsten, iron, and manganese. Some minor amounts of elements such as silicon and carbon may also be present. Examples of such materials include Stellite®, Inconel®, Hastelloy® and Talonite®.

The jacket 303 can be made of a corrosion-resistant material that can include any of the materials noted herein. In particular instances, the jacket 303 can incorporate a plug 392 made of a material suitable for use as a galvanic corrosion inhibitor. In certain designs, the plug 392 can be contained within the body of the jacket 303 and intersecting the surface 311 of the jacket 303 such that the plug can be exposed to the downhole environment and act as a galvanic corrosion inhibitor to reduce the potential corrosion to other portions of the cutting element 300. Some suitable materials can include a metal or metal alloy, such as zinc or zinc-based material.

Notably, the plug 392 can be positioned within the jacket 303 such that it can be exposed to the downhole environment. Other embodiments may use a plug 392 contained within the jacket 303 and substrate 301. It will be appreciated that the plug 392 can be placed in a position that maintains a sufficient electrical contact with the environment and maintain a suitable electrical conductivity to act as a galvanic corrosion inhibitor. In fact, while FIG. 3A has illustrated the plug 392 as a monolithic piece of material within the jacket 303, other embodiments can employ different forms of the plug 392. For example, certain embodiments can utilize a layer of the galvanic corrosion inhibiting material (e.g., a coating) overlying a portion of the jacket 303. More particularly, the entire exterior surface of the jacket 303 can be coated by the galvanic corrosion inhibiting material. In yet other designs, the galvanic corrosion inhibiting material can be in the form of a particulate material, which can be uniformly dispersed in the material of the jacket 303. The particulate material can be uniformly dispersed throughout the entire volume of the jacket 303. In certain embodiments, the particulate material can be selectively deposited in regions of the jacket 303, for example, in regions of the jacket spaced away from the interface between the superabrasive layer 302 and the substrate 301.

Additionally, the jacket 303 can be made of a material such as a carbide, nitride, boride, oxide, carbon-based material, and a combination thereof. In accordance with one particular embodiment, the jacket 303 can be a cermet material. Particular examples of suitable cermet materials include tungsten carbide material or cemented tungsten carbide.

According to certain other designs, the cutting element 300 can be formed such that the jacket 303 comprises a polycrystalline material. The polycrystalline material can be an elemental composition, ceramic, a cermet, a metal, a metal alloy, and a combination thereof. For example, the jacket 303 can be made of a material including polycrystalline diamond. In particular instances, the jacket 303 can be formed entirely of polycrystalline diamond. In another embodiment, the jacket 303 can be formed entirely of cubic boron nitride. Yet, other designs may utilize a jacket 303 wherein a portion of the jacket 303 comprises polycrystalline diamond, such as in the form of an exterior layer, film, or series of layers.

In still other designs, the cutting element 300 can be formed such that the jacket 303 is made of a material including an organic material. Some suitable organic materials can include thermoset, thermoplastics, elastomers, and a combination thereof. For example, the jacket 303 can include a polymer material such as polyamides, polyimides, polyesters, polyethers, polyurethanes, gels, polyxylylenes, silicone, fluoropolymers, and a combination thereof.

Still, in certain embodiments, the jacket 303 and substrate 301 may be formed such that they comprise the same general composition, yet the concentration of certain species may differ between the jacket 303 and the substrate 301. For example, the jacket 305 and substrate 301 can be made of a carbide material, specifically tungsten carbide, and yet the jacket 305 may be formed of a carbide having a different composition than that of the substrate 301. That is, the jacket 305 can be formed such that it contains a different element, such as a different metal species, particularly a different content of a catalyst metal species (e.g., cobalt) as compared to the composition of the substrate 301.

Referring to FIG. 3B, a general perspective illustration of the cutting element of FIG. 3A is provided with a cut-out portion for an internal view of components of the cutting element. FIG. 3B does not show the particular chamfered edges and is provided to generally illustrate the orientation of the components of the cutting element 300 with respect to each other, including a cut-out portion for a clearer understanding of the orientation of the substrate 301 and the superabrasive layer 302. As illustrated, the jacket 303 can surround the cutter body 350 including the substrate 301 and at least a portion of the side surface 306 of the superabrasive layer 302. As described herein, and as will be appreciated, while FIG. 3B illustrates a cutting element 300 having a generally cylindrical shape, other polygonal shapes are contemplated, such as elliptical, triangular, rectangular, trapezoidal, hexagonal, irregular, and the like.

FIG. 4A includes a cross-sectional illustration of a cutting element in accordance with an embodiment. The cutting element 400 includes components described herein, particularly including a cutter body 450 comprising a substrate 301 and a superabrasive layer 302 overlying an upper surface 307 of the substrate 301. The cutting element 400 further includes a jacket 303 extending over the side surface 306 of the superabrasive layer 302 and the side surface 305 of the substrate 301. Notably, the upper surface 307 of the substrate 301 is formed to have a contoured region 401. The contoured region 401 can be formed in the upper surface 307 of the substrate 301 to aid reduction of stresses in the superabrasive layer 302. The contoured region 401 can be formed such that it includes a protrusion 402 extending axially along the longitudinal axis 308 and displaced at a position along the longitudinal axis 308 that is different than other points along the upper surface 307. It will be appreciated, that the contoured region 401 is illustrated as including a protrusion 402, but other shapes and contours may be used. For example, a series of protrusions or series of grooves may be utilized, and moreover may be patterned of shapes may be utilized on the upper surface 307, such as an arrangement of protrusions appearing as spokes extending radially along the upper surface 307 of the substrate 301 from the center of the upper surface 307 to the side surface 306 of the substrate 301.

Additionally, the cutting element 400 can include a coating 411 overlying a portion of the substrate 301. As illustrated, and according to certain designs, the coating 411 can overlie the outer surface 311 of the jacket 303, and more particularly, can be abutting the outer surface 311 of the jacket 303. In fact, the coating 411 can include a film that overlies all the external surfaces of the jacket 303, including a surface portion 415 overlying the front surface 346 of the jacket 303, a surface portion 414 overlying the chamfered surface 347 of the jacket 303, a surface portion 413 overlying the outer surface 311 of the jacket 303, and even a surface portion 417 overlying the chamfered surface 323 of the jacket 303. The coating 411 can provide additional corrosion resistance and erosion resistance to the jacket 303.

Suitable materials for use in the coating 411 can include inorganic materials, organic materials, and a combination thereof. Notably, the coating 411 can include the same materials of the jacket 303. For instance, the coating 411 can be formed of an inorganic material such a as a ceramic, cermet, metal, metal alloy and a combination thereof. In particular embodiments, the coating 411 can employ a super-alloy material.

In still other instances, the coating 411 can be formed of a ceramic material, such as an oxide, carbide, nitride, boride, and a combination thereof. Some designs may incorporate an abrasive material in the coating 411. Some such suitable abrasive materials can include superabrasive materials, like cubic boron nitride, diamond, and a combination thereof. In at least one embodiment, the coating 411 can be formed entirely of cubic boron nitride. In another embodiment, the coating 411 can be formed entirely of polycrystalline diamond.

While the coating 411 is illustrated as a layer overlying the entire external surfaces of the jacket 303, certain designs can utilize a coating 411 that overlies only a fraction of the total external surface of the jacket 303. For example, the coating 411 can be formed such that it overlies the external surfaces of the jacket 303 proximate to the front of the cutting element 400, and particularly the surfaces closes to the superabrasive layer 302, which are configured to be engaged in the cutting process. The coating 411 can selectively overlay particular portions of the jacket, including for example, the upper surface 346 of the jacket, the chamfered surface 347 of the jacket, at least a fraction of the outer surface 311 of the jacket 303, at least a fraction of the inner surface 310 of the jacket 303, and a combination thereof. In particular instances, the coating 411 can overlie, and in particular, can abut the inner surface 310 of the jacket 303, such that the coating 411 is disposed between the substrate 301 and the jacket 303. Such embodiments may be particularly useful in the context of releasable jackets 303, which can be removed from the substrate 301.

FIG. 4B includes a cross-sectional illustration of a cutting element in accordance with an embodiment. The cutting element 420 includes components described herein, particularly including a cutter body 450 comprising a substrate 301 and a superabrasive layer 302 overlying an upper surface 307 of the substrate 301. The cutting element 420 further includes a jacket 303 extending over the side surface 306 of the superabrasive layer 302 and the side surface 305 of the substrate 301. Notably, the upper surface 307 of the substrate 301 is formed to have a contoured region 421 having a different contour than the embodiment of FIG. 4A. In fact, the upper surface 307 of the substrate 301 can be contoured to have protrusions 422, 423, and 424, which can extend into complementary grooves within the superabrasive layer 302. The protrusions 422-424 can extend through a circumference (or other peripheral measurement) and define a series of arcs within the upper surface 307 of the substrate 301 to reduce mechanical strains on the superabrasive layer 302 during formation and use.

FIGS. 4C and 4D include cross-sectional illustrations of cutting elements according to embodiments. The cutting element 470 of FIG. 4C includes components described herein, particularly including a cutter body 450 comprising a substrate 301 and a superabrasive layer 302 overlying an upper surface 307 of the substrate 301. The cutting element 470 further includes a jacket 303 extending over the side surface 306 of the superabrasive layer 302 and the side surface 305 of the substrate 301. Notably, the jacket 303 is formed to overlay at least a portion of the rear surface 396 of the substrate 301. According to certain embodiments, the jacket 303 can encapsulate a majority of the external surfaces (e.g., side surface 305 and rear surface 396) of the substrate 301. In certain embodiments, as illustrated in FIG. 4C, a portion of the jacket 303 is configured to extend over, and abut, a portion of the rear surface 396 of the substrate 301. Such a configuration can facilitate improved corrosion-resistance and/or erosion-resistance of the cutting element 470 in downhole applications.

FIG. 4D includes a cross-sectional illustration of a cutting element 480 similar to that of FIG. 4C, with the distinction that the jacket 303 is overlying the entire rear surface 396 of the substrate 301. As such, it is contemplated that embodiments herein can utilize a jacket 303 having various configurations of coverage of the substrate 301 to provide improved corrosion-resistance and/or erosion resistance.

FIGS. 5A-5C include cross-sectional illustrations of cutting elements according to embodiments, In particular, the FIGS. 5A-5C include illustrations of embodiments using a jacket having a variable thickness that can have a changing thickness with a change in position in an axial direction, a change in position in a radial direction, or a combination of such directions. The thickness of the jacket can be a gradual variation (e.g., a tapered form), an abrupt variation (e.g., a stepped configuration), a series of discrete, abrupt variations, or a combination thereof. The thickness of the jacket can be varied such that the change in thickness is asymmetric. The asymmetry can be based around the longitudinal axis, a radial axis, or a combination thereof. For example, the inner and outer surfaces of the jacket can be varied such that the change in thickness is asymmetric with regard to the contours of the inner and outer surfaces.

FIG. 5A includes a cross-sectional illustration of a cutting element in accordance with an embodiment. The cutting element 500 includes a cutter body 550 employing a substrate 301 having a superabrasive layer 302 overlying the upper surface 307 of the substrate 301. The cutting element 500 further includes a jacket 503 overlying a side surface 306 of the superabrasive layer 302 and a side surface 305 of the substrate 301. Generally, cutting elements of any of the embodiments herein can be formed such that the jacket can have a thickness as measured between the inner surface 510 and the outer surface 311 that varies. That is, the thickness of the jacket 503 can vary in an axial direction, a radial direction, or a combination thereof.

As illustrated in FIG. 5A, the jacket 503 is formed such that its thickness varies axially, changing in thickness at different positions along the longitudinal axis 308 of the cutter body 550. In particular embodiments, the jacket 503 can have a tapered shape, such that the thickness of the jacket 503 within the region 504 adjacent to the superabrasive layer 302 has a lesser thickness than the thickness of the jacket within region 505 adjacent to the rear surface 396 of the substrate 301. The tapered shape of the jacket 503 can be achieved by utilizing an outer surface 311 that extends substantially parallel to the longitudinal axis and an inner surface 510 that extends at an angle to the longitudinal axis 308. The side surface 305 of the substrate 301 can complement the inner surface 510 of the jacket 503 and extend at an angle to the longitudinal axis 308. Thus, in certain embodiments utilizing a jacket 503 having a tapered shape, the side surface 305 of the substrate can be tapered, such that the shape of the substrate 301 can have an axially varying thickness, and in particular, can have a frustoconical shape.

The cutting element 500 can be formed in a one-piece construction or a two-piece construction, which will be described in more detail herein. The axially varying thickness of the jacket 503 can facilitate an improved bond between the substrate 301 and the jacket 503, particularly when the jacket 503 is affixed to the substrate 301 of the cutting element, which is indicative of a two-piece construction.

FIG. 5B includes a cross-sectional illustration of a cutting element in accordance with an embodiment. The cutting element 520 includes a cutter body 550 employing a substrate 301 having a superabrasive layer 302 overlying the upper surface 307 of the substrate 301. The cutting element 520 includes a jacket 523 overlying the side surface 306 of the superabrasive layer 302 and the side surface 305 of the substrate 301. Unlike the jacket 503 of FIG. 5A, the jacket 523 of FIG. 5B can have a tapered shape, wherein the thickness of the jacket 523 in the region 504 adjacent to and abutting the rear surface 316 of the superabrasive layer 302 can be greater than a thickness of the jacket 523 in the region 505 at the rear surface 525 of the jacket 523. As illustrated, the cutting element 520 can achieve a jacket 523 having a tapered shape by utilizing an inner surface 526 that is angled relative to the longitudinal axis 308 and outer surface 311 of the jacket 523, wherein the outer surface 311 and the longitudinal axis 308 extend along directions substantially parallel to each other.

It will be appreciated that the jackets of embodiments herein can also achieve an axially variable thickness by changing the contour of the outer surface 311 of the jacket. That is, the inner surface 510 can be formed such that it extends parallel to the longitudinal axis 308 of the cutter body 550, but the outer surface 311 of the jacket 523 is angled relative to the longitudinal axis 308 of the cutter body 550.

FIG. 5C includes a cross-sectional illustration of a cutting element in accordance with an embodiment. The cutting element 560 includes a cutter body 550 employing a substrate 301 having a superabrasive layer 302 overlying the upper surface 307 of the substrate 301. The cutting element 560 includes a jacket 563 overlying a side surface 306 of the superabrasive layer 302 and a side surface 305 of the substrate 301. According to the embodiment of FIG. 5C, the jacket 563 has a variable thickness that changes thickness at different axial positions along the longitudinal axis 308 at discrete intervals. As such, the jacket 563 can have an inner surface 561 comprising a plurality of discrete steps, wherein each of the steps can have a different axial and radial position relative to each other. The jacket 563 therein can have a difference in thickness at each of the discrete steps.

As illustrated in the embodiment of FIG. 5C, the jacket 563 can have a greater thickness in the region 564 as compared to the thickness of the jacket 563 in the region 565. The jacket 563 can have an inner surface 561 comprising a plurality of discrete steps, including for example a surface 566 defining a first step having a first thickness and a second surface 568 displaced axially from the surface 566 and radially displaced from the surface 566 in a position closer to the outer surface 311 of the jacket 563. The surfaces 566 and 568 are joined by a surface 567 extending substantially perpendicular to the longitudinal axis 308 and the surfaces 566 and 568. Such a configuration facilitates the formation of an inner surface 561 comprising the discrete steps to form the jacket 563 having an axially varying thickness along the length of the jacket 563 from the upper surface 346 to the rear surface 569.

The substrate 301 can be formed, either through a direct forming process (such as casting or molding) or by machining to have a side surface 305 having a complementary contour to the inner surface 561 of the jacket 563. That is, the substrate 301 can have a side surface 305 comprising a plurality of steps for complementary engagement with the inner surface 561 of the jacket 563. Such a design can facilitate an interlocking relationship between the two components.

It will be appreciated that other embodiments can be utilized wherein the thickness of the jacket 563 varies in a different manner, for example, a jacket wherein the thickness is greater in the region 565 as compared to the thickness of the jacket in the region 564. Moreover, it will be appreciated that while the illustrated embodiments demonstrates a symmetrical, stepped configuration for the inner surface 561 of the jacket 563, other contours may be utilized. For example, the inner surface 561 can include steps of different radial height and/or axial length as compared to other steps along the inner surface 561. Additionally, the cutting elements of embodiments herein can utilize a combination of features, such as a jacket having a combination of a tapered surface and stepped surface.

FIG. 6A includes a cross-sectional illustration of a cutting element in accordance with an embodiment. The cutting element 600 can include a cutter body 650 employing a substrate 301 having a superabrasive layer 302 overlying the upper surface 307 of the substrate 301. The cutting element 650 can include a jacket 603 overlying the side surface 306 of the superabrasive layer 302 and the side surface 305 of the substrate 301. According to the embodiment of FIG. 6A, the jacket 603 can have a flange 648 that includes an inner surface 606 that extends axially over the entire length of the side surface 306 of the superabrasive layer 302 between the rear surface 316 and the chamfered surface 345. In such embodiments, the flange 648 is placed in a direct cutting position configured to share the cutting load with the superabrasive layer 302. It will be appreciated, that such a configuration may be most suitable for use with a jacket comprising an abrasive material, such as a superabrasive material (e.g., polycrystalline diamond or cubic boron nitride).

FIG. 6B includes a cross-sectional illustration of a cutting element in accordance with an embodiment. The cutting element 620 can include a cutter body 650 employing a substrate 301 having a superabrasive layer 302 overlying the upper surface 307 of the substrate 301. The cutting element 650 can include a jacket 603 overlying the side surface 306 of the superabrasive layer 302 and the side surface 305 of the substrate 301. Notably, the jacket 603 can have a particularly shaped flange 648 overlying and abutting the side surface 306 of the superabrasive layer 302. In accordance with at least one embodiment, the flange 648 is formed to have an upper surface 607 that extends at an angle to the longitudinal axis 308, such that it can be a tapered surface. Particularly, the upper surface 607 can be a tapered surface terminating at the edge between the side surface 306 and chamfered surface 345 of the superabrasive layer 302. The upper surface 607 can extend at various angles and for various lengths depending upon the intended application. Moreover, it will be appreciated that the upper surface 607 can be formed with a curvilinear shape, such that the upper surface 607 can be a radiused surface in certain embodiments.

FIG. 7 includes a cross-sectional illustration of a cutting element in accordance with an embodiment. FIG. 7 includes a cutting element 700 having a cutter body 750 employing a substrate 301 and a superabrasive layer 302 overlying an upper surface 307 of the substrate 301. Additionally, the cutting element 700 includes a jacket 703 that can be abutting a surface of the superabrasive layer 302. In particular, the superabrasive layer 302 can include a flange region 707 that extends axially along the side surface 305 of the substrate 301. The jacket 703 can be formed to have an upper surface 719 that is flush with and directly contacting a surface of the flange region 707. The flange region 707 can include the same materials and properties of the superabrasive layer 302 as described herein. In particular, the flange region 707 can utilize a polycrystalline diamond material, and in certain instances, can consist essentially of a polycrystalline diamond material, offering additional corrosion-resistance and/or erosion resistance. It will be appreciated, that while the jacket 703 is not illustrated as overlying a side surface of the superabrasive layer, and particularly a side surface of the flange region 707, such embodiments are contemplated.

As illustrated, the flange region 707 can be formed to extend axially to a position behind rear surface 316 of the superabrasive layer, such that the surface 708 of the flange region 707 is closer to the rear surface 396 of the substrate 301 as compared to the distance between the surface 316 of the superabrasive layer 302 and the rear surface 396 of the substrate. Notably, the flange region 707 can be a portion of the superabrasive layer 302 that can extend axially along a portion of the side surface 305 of the substrate 301. Such a design can provide additional protection from erosion and/or corrosion to the interface between the rear surface 316 of the superabrasive layer 302 and the upper surface 307 of the substrate 301.

The flange region 707 can be defined by a surface 708 that extends substantially perpendicular to the longitudinal axis 308 and terminates at an upper surface 719 of the jacket 703. Additionally, the flange region 707 can be further defined by an inner surface 711 connected to the rear surface 316 and the surface 708 in a direction substantially parallel to the longitudinal axis 308 of the cutter body 750. The surface 711 can overlie, and in particular, can be abutting the side surface 305 of the substrate 301. The surface 709 can further define the flange region and extend between the chamfered surface 345 and the surface 708.

The flange region 707 can have a length (L_(f)) measured as a distance in an axial distance along the longitudinal axis 308 between a midpoint at the rear surface 316 of the superabrasive layer 302 (i.e., the intersection between the rear surface 316 of the superabrasive layer 302 and the longitudinal axis 308) and the rear-most point (i.e., closest to the rear surface 396 of the substrate 301) on the surface 708. In certain embodiments, the flange region 707 can have a length (L_(f)) that is at least about 2% of the total length (L_(ce)) of the cutting element as defined by the equation [(L_(ce)−L_(f))/L_(ce)]×100%, wherein L_(ce) is the length of the cutting element 700 and L_(f) is the length of the flange region 707. According to certain other embodiments, the flange region 707 can have a length of at least about 5%, at least about 10%, or even at least about 15% based on the equation above. Yet, some embodiments can utilize a flange region 707 having a length within a range between about 2% and about 50%, such as between about 2% and about 40%, between about 5% and about 30%, between about 5% and about 20%, or even between about 10% and about 25% of the total length of the cutting element 700.

The cutting element 700 can be formed as single, monolithic article in a one-step forming process (e.g., a HP/HT forming process), or alternatively, the cutting element 700 can be formed using a two-step forming process, which may employ formation of the components separately and a subsequent joining step between components. While the jacket 703 is illustrated as having a shape wherein the upper surface 719 terminates at the surface 708, other embodiments can utilize a jacket 703 having a flange portion (as illustrated in other embodiments) that is overlying and abutting the surface 709 of the flange region 707 of the superabrasive layer 302.

FIGS. 8A-8B include cross-sectional illustrations of cutting elements in accordance with embodiments. Generally, cutting elements of embodiments herein can utilize a jacket and cutter body that may be mechanically interlocked with each other. That is, the jacket and cutter body can be formed of a single, monolithic article in a one-step forming process. In such instances, the jacket and the cutter body can be integrally bonded to each other without a noticeable seam or bond joint. In still other embodiments, the jacket and cutter body can be affixed to each other using a two-step forming process, wherein the cutter body is formed first and the jacket is formed separately and the two components are mechanically affixed to each other. In such instances, the jacket can be affixed to the cutter body using different mechanisms including a releasable mechanical connection such that many jackets can be interchanged with the cutter body, a permanent fixation using a bond joint (e.g., permanently brazed coupling assembly), fasteners, interlocking connections, interference fit connections, taper-lock connections, a combination thereof, and the like. Mechanically interlocking connections between the cutter body and the jacket can be accomplished by incorporation of interfacial surface features on the inner surface of the cutter body, particularly the substrate, and the jacket. Notably, such interfacial features can include the use of complementary engaging features that are designed to interlock the jacket and cutter body at the interface between the jacket and substrate. Some suitable examples of interfacial surface features can include grooves and/or protrusions extending axially and/or radially along the inner surface of the jacket and cutter body, honeycomb structures, threaded surfaces, and the like.

One such design of mechanically interlocking orientation between the components is provided in FIG. 8A. FIG. 8A includes a cross-sectional illustration of a cutting element in accordance with an embodiment. The cutting element 800 includes a cutter body 850 comprising a substrate 301 and a superabrasive layer 302 overlying an upper surface 307 of the substrate 301. A jacket 803 can extend axially over the side surface 306 of the superabrasive layer 302 and the side surface 305 of the substrate 301. The jacket 803 and the substrate 301 can include a contoured region along their respective inner surfaces 310 and 305 for complementary engagement and mechanically interlocking the two components. Contoured regions as used herein can reference protrusions, grooves, lips, or any other surface features suitable for interlocking engagement between the jacket 803 with the substrate 301. As illustrated in FIG. 8A, the jacket 803 comprises a protrusion 801 extending radially inward along the inner surface 310 that is configured to be engaged with a complementary groove 805 within the side surface 305 of the substrate 301. As will be appreciated, the protrusion 801 may extend for a portion of the peripheral (e.g. circumferential) dimension of the inner surface 310 of the jacket 803. That is, the protrusion 801 can extend peripherally along the inner surface 310 of the jacket 803 for a distance of at least about 45°, at least about 90°, or even at least about 180°. In certain instances, the protrusion 801 may extend for the full peripheral dimension of the inner surface 310 of the jacket 803 (i.e., 360°). Likewise, the complementary groove 805 may extend for the same distance for proper complementary engagement of the groove 801 therein.

Notably, the protrusion 801 can be placed in an axial position along the length of the jacket 803, such that it is proximate to the rear surface 314 of the jacket 803. In particular, the protrusion 801 can be axially spaced apart from the rear surface 316 of the superabrasive layer 302 to avoid potential weakening of the mechanical bond between the substrate 301 and the superabrasive layer 302. As such, embodiments herein may utilize a protrusion (and any other surface features) for complementary engagement of the substrate 301 and the jacket 803 at a position that is closer to the rear surface 396 of the substrate 301 than the rear surface 316 of the superabrasive layer 302.

FIG. 8B includes a cross-sectional illustration of a cutting element in accordance with an embodiment. The cutting element 820 includes a cutter body 850 comprising a substrate 301 and a superabrasive layer 302 overlying an upper surface 307 of the substrate 301. A jacket 803 can extend axially over the side surface 306 of the superabrasive layer 302 and the side surface 305 of the substrate 301. The jacket 803 and the substrate 301 can include a contoured region along their respective inner surfaces 310 and 305 for complementary engagement and mechanically interlocking the two components. As illustrated in FIG. 8B, the jacket 803 comprises a groove 829 extending radially outward into the body of the jacket 803 to define a cavity therein. A complementary protrusion 821 extends radially outward from the side surface 305 of the substrate 301 and is configured to engage the groove 829 and mechanically interlock the substrate 301 and the jacket 803.

In particular, the groove 829 can be defined by a linear surface 822 and curved surface 823, a combination of which can aid coupling and proper placement between the substrate 301 and the jacket 803. Such a structure of the groove 829 and the protrusion 821 can facilitate proper seating between the jacket 803 and substrate 301 for proper bonding between the two components. Alternatively, the groove 829 and protrusion 821 can be shaped such that the jacket 803 is releasably engaged with the substrate 301, for use of interchangeable jackets.

FIG. 9A includes a cross-sectional illustration of a cutting element in accordance with an embodiment. In particular, FIG. 9A includes a cutting element 900 having those components described in embodiments herein, including a cutter body 950 comprising a superabrasive layer 302 overlying an upper surface 307 of a substrate. The cutting element 900 further includes a jacket, which is in the form of a collar 901, which can extend axially along the side surface 305 of the substrate 301 and along at least a portion of the side surface 306 of the superabrasive layer 302. Notably, the collar 901 is a particular formulation of the jacket of embodiments herein, and is distinguished from other jackets because the collar 901 extends for a fraction of the total length (L_(ce)) of the cutting element 900. The collar 901 can have an exterior side surface 903 that extends parallel to the side surface 305 of the substrate 301 and parallel to the longitudinal axis 308 of the cutter body 950. The collar 901 can further include a front surface 902, which can be a chamfered surface, extending at an angle to the longitudinal axis 308. Additionally, the collar 901 can be defined by a rear surface 904 extending from the exterior side surface 903 and connected to the side surface 305 of the substrate 301. The collar can have the same features and properties of the jackets described in accordance with embodiments herein, particularly with regard to the use of corrosion-resistance and/or erosion resistant materials.

The collar 901 can be mechanically connected to the cutter body 950, and more particularly, mechanically connected to the substrate 901. In certain instances, the collar 901 can be permanently mechanically connected (i.e., affixed) to the cutter body 950. In instances wherein the collar 901 is affixed to the substrate 301, the means for affixing the two components can include various implements, such as fasteners, interlocking connections, bonding mechanisms (e.g., brazing), a combination thereof and the like. In other designs, the collar 901 can be releasably attached to the cutter body 950, such that after use of the cutting element 900 and sufficient wear to the collar 901, the collar 901 can be replaced with a new collar and the cutting element may be reused. Some suitable mechanisms for implementing releasable engagement between the collar 901 and the substrate 301 can include fasteners, interlocking connections, snap-fit connections, taper-fit connections, temperature-induced fitting procedures using a temperature differential between components, bonding compounds and mechanisms (e.g., adhesives, etc) a combination thereof and the like.

According to the illustrated embodiment of FIG. 9A, the collar 901 can have an engagement arm 906 that is configured to extend radially inward, into the body of the substrate 301 within a complementary groove 905 within the side surface 305 of the substrate 301. The engagement arm 906 and groove 905 can be an interlocking connection for mechanically affixing the collar 901 to the substrate 301. In other embodiments, the engagement arm 906 and groove 905 can be a releasable connection, such that the collar 901 can be removed from the cutter body 950.

Moreover, the engagement arm 906 can be positioned such that it extends from the rear surface 904 of the collar 901. The position of the engagement arm 906 ensures that it is engaged within the interior of the substrate at a sufficient distance from the rear surface 316 of the superabrasive layer 302 to avoid weakening the bond between the superabrasive layer 302 and the substrate 301.

As further illustrated in the embodiment of FIG. 9A, the collar 901 can have a length (L_(c)) as measured in an axial direction parallel to the longitudinal axis 308. The length of the collar 901 can extend for a fraction of the entire length (L_(ce)) of the cutting element as defined by the equation [(L_(ce)−L_(c))/L_(ce)]×100%, wherein L_(ce) is the length of the cutting element and L_(c) is the length of the collar 901. Notably, independent of the length, a portion of the collar 901 can be configured to cover the interface between the superabrasive layer 302 and the substrate 301 defined by the upper surface 307 of the substrate 301 and rear surface 316 of the superabrasive layer 302.

FIG. 9B includes a perspective view of the cutting element of FIG. 9B. As illustrated, the collar 901 can extend around the periphery of the outer side surface 305 of the substrate 301. In particular, as illustrated, the collar 901 overlies the interface between the substrate 301 and the superabrasive layer 302 to reduce the damage to the interface due to the corrosive and erosive downhole environment. According to one particular embodiment, the collar 901 can extend around the entire periphery (i.e., circumference) of the cutter body 950.

FIG. 9C includes a cross-sectional illustration of a cutting element in accordance with an embodiment. In particular, FIG. 9C includes a cutting element 910 having those components described in embodiments herein, including a cutter body 950 comprising a superabrasive layer 302 overlying an upper surface 307 of a substrate. The cutting element 910, like the cutting element 900, includes a jacket, which is in the form of a collar 911, which can extend axially along the side surface 305 of the substrate 301 and along at least a portion of the side surface 306 of the superabrasive layer 302. The collar 911 of FIG. 9C differs from the collar 901 of FIG. 9A in that the collar 911 has a greater length and differently shaped engagement arm 917 extending radially inward into the body of the substrate 301. The collar 911 can include an upper surface 912 angled relative to the longitudinal axis 308 and overlying, and particularly, abutting the side surface 306 of the superabrasive layer 302. The collar 911 further includes an exterior side surface 913 extending between the upper surface 912 and a rear surface 914 substantially parallel to the longitudinal axis 308.

The collar 911 includes an engagement arm having a particular re-entrant shape. The re-entrant shape includes surfaces 915 and 918 that can be angled relative to each other such that the surface 916 has a greater length than a length between the surfaces 918 and 915 at the side surface 305 of the substrate 301. Given the shape of the engagement arm 917, the collar 911 may not necessarily be removed in a direction laterally and can avoid removal during operation. The collar 911 may be engaged in the complementary groove of the substrate 301 by sliding the collar peripherally along an engagement groove within the substrate 301 until the engagement arm 917 is contained within the groove.

Unlike the collar 901 of FIG. 9A, the collar 911 may not necessarily extend through the entire periphery (i.e., circumference) of the cutter body 950. FIG. 9D includes a perspective view of the cutting element 910 of FIG. 9C as placed in the blade 922 of a drill bit. As illustrated, the cutting element 910 is configured within the surface of the drill bit, such that the collar 911 extends around the circumference of the cutter body 950 and is in a cutting position configured to potentially engage downhole formations and provide suitable corrosion-resistance and/or erosion resistance for the interface between the substrate 301 and the superabrasive layer 302.

FIG. 9E includes a cross-sectional illustration of the cutting element of FIG. 9A in a cutting position according to an embodiment. As illustrated, the cutting element 910 when contained within a drill bit can be angled relative to a surface 940 to remove material from the surface 940, which is a typical configuration in a downhole material removal process. As illustrated, the collar 911 of the cutting element is configured to engage a portion of the surface 940 within the region 941 after the surface 940 is engaged by the superabrasive layer 302. The region 941 can be an erosive and corrosive environment, which can attack the interface between the substrate 301 and the superabrasive layer 302. The collar 911 can provide suitable protection against this environment and improve the cutting capabilities and lifetime of the cutting element 910.

The cutting elements herein can have a jacket that is designed to have a different composition than the composition of the substrate. The difference in composition can be a difference in at least one element, a compound, or the entire composition. According to one embodiment, the jacket can have a composition that varies from the substrate based on the content of a single species (e.g., a catalyst material), such that the jacket and the substrate can generally have the same basic composition, yet the content of certain elements contained within the composition are varied. For example, particular embodiments can have a jacket having an average cobalt content (or any other content of a catalyst material) that is different than the average cobalt content of the substrate. In certain embodiments, the jacket can have an average cobalt content that is at least 1% less than the average cobalt content of the substrate. For example, the substrate can have an average cobalt content of 12%, and accordingly, the jacket can have an average cobalt content of 11% or less.

In other instances, the difference in the cobalt content between the jacket and the substrate can be greater, such that the average cobalt content of the jacket is at least about 3% less, at least about 5% less, at least about 8% less, or even at least about 10% less. In accordance with at least one embodiment, the average cobalt content of the jacket can be within a range between about 1% and about 15% less, such as between about 1% and about 12% less, or even between about 3% and about 10% less than the average cobalt content of the substrate. The foregoing has made specific reference to cobalt, however, cutting elements utilizing other catalyst materials, such as iron, nickel, and even a combination of catalyst materials, can utilize the same differences in composition between the substrate and the jacket.

Additionally, the cutting elements of the embodiments herein can employ a jacket having a different microstructure than the microstructure of the substrate. The microstructure can be characterized by the grade of material used, the average grain size, shape of the grains, distribution of grain sizes, and the like. According to one embodiment, the jacket is formed from a grade of tungsten carbide that is different than the grade of tungsten carbide used to form the substrate. In still other embodiments, the jacket comprises an average grain size of tungsten carbide that is different than the average grains size of the substrate. In a particular design, the jacket is formed of tungsten carbide having a smaller average grain size than the average grains size of the substrate, which may provide improved erosion-resistance. While such distinctions have mentioned the use of tungsten carbide, it will be appreciated that such distinctions in microstructure between the substrate and the jacket can be utilized for any of the materials described herein.

According to embodiments of certain cutting elements, the jacket can be formed from a series of films or layers of material, such that the composition of the jacket can be an axially varying composition, a radially varying composition, and a combination thereof. For example, in certain jackets having a radially varying composition, the composition of the jacket at a first radial position can be different than the composition of the jacket a second radial position. Likewise, for axially varying compositions, the composition of the jacket between a first and second position axially spaced apart from each other within the jacket can have different compositions.

In particular, the varying compositions can be a gradient of a composition, wherein the composition changes gradually with a change in positions along the body of the jacket. As such, in embodiments using a gradient of axially varying and/or radially varying composition, the jacket may not necessarily be formed of discrete layers or films of material. Rather, the jacket can be a monolithic article, and more particularly, the substrate and jacket can be integrally bonded to form a monolithic article, wherein the composition gradually varies in an axial and/or radial direction through the entire substrate/jacket assembly.

The difference in composition for such jackets can be based on a difference of the entire composition or a single chemical species (e.g., element), wherein the content (mass or volume) of the particular species within the composition changes with a change in the radial and/or axial position on the jacket. For example, in certain instances, the jacket can be formed of tungsten carbide, and the tungsten carbide composition can have a particular content of a catalyst material, such as cobalt. In particular embodiments, the cobalt composition of the jacket can vary axially or radially. That is, in one design, the jacket comprises a gradient of cobalt content along the length of the jacket body, such that the cobalt content within the jacket gradually changes along the length of the jacket, thus defining an axially varying cobalt gradient. In other embodiments, the jacket can employ a radially varying cobalt content, such that the cobalt content within the jacket gradually changes along the thickness of the jacket from the inner surface to the external side surface of the jacket. Still, it will be appreciated that a jacket body employing a number of layers, wherein the layers can have a different chemical composition with respect to each other, can include a composite arrangement, wherein for example, one layer comprises a first chemical composition (e.g., tungsten carbide) and a second layer comprises a second chemical composition (e.g., polycrystalline diamond) different than the first chemical composition.

FIGS. 10 A-10C provide cross-sectional illustrations of cutting elements employing jackets having radially varying and/or axially varying compositions. FIG. 10A includes a cross-sectional illustration of a cutting element according to an embodiment. The cutting element 1000 can include those components described herein, notably a cutter body 1050 including a substrate 301 and a superabrasive layer 302 overlying the upper surface 307 of the substrate 301. The substrate 301 can further include a jacket 1003 having an inner surface 310 overlying, and in particular, abutting the side surface 305 of the substrate 301. The jacket 1003 can further include an upper surface 1002 that is abutting the rear surface 316 of the superabrasive layer 302. Notably, according to the illustrated embodiment, the jacket 1003 can be formed such that there may not necessarily be a flange overlying the side surface 306 of the superabrasive layer 302, however, it will be appreciated that such configurations can be used.

The jacket 1003 can have a radially varying composition. As illustrated, the jacket 1003 can have layered regions 1008, 1009, and 1010 that are radially spaced apart from each other and extend generally parallel to the longitudinal axis 308 of the cutter body 1050. In certain embodiments, the layered regions 1008-1010 can be separated by discrete interfaces, such that the layered regions 1008 and 1009 can be separated at an interface 1012 that can extend generally parallel to the longitudinal axis 308 of the cutter body 1050. Moreover, the layered regions 1009 and 1010 can be separated at an interface 1011 that can extend generally parallel to the longitudinal axis 308 of the cutter body 1050.

Each of the layered regions 1008-1010 can represent regions within the jacket having compositions that can be different from each other. For example, the position 1004 within the layer 1008 is radially spaced apart from the position 1005 within the layer 1009, and particularly, the position 1004 can have a composition that is different from the composition of the position 1005. Moreover, the position 1005 within the layer 1009 is radially spaced apart from the position 1006 within the layer 1010, and particularly, the position 1005 can have a composition that is different from the composition of the position 1006. Likewise, the positions 1004 and 1006, which are radially spaced apart from each other, can have a difference in composition. The layered region 1008-1010 can have compositions wherein the content of at least one species is different as compared to the content of the same species within any of the other layered regions 1008-1010. Additionally, the layered regions 1008-1010 can have a composition, wherein at least one chemical species (e.g., a catalyst material) is present within one of the layered regions and can be absent from one of the other layered regions 1008-1010. Furthermore, it will be appreciated that while the jacket 1003 is illustrated as having three layered regions, more or less layered regions can be used to construct the jacket 1003.

According to one embodiment, the jacket 1003 can have a radially varying composition, such that the content of a catalyst material, such as cobalt, at the positions 1004, 1005, and 1006 are different compared to each other. In fact, in certain designs, the layered region 1008 can have an average cobalt content that is greater than the average cobalt content within the layered regions 1009 and 1010. Moreover, the layered region 1009 can have an average cobalt content that is greater than the average cobalt content within the layered region 1010. Accordingly, the cobalt content of the composition at position 1004 can be greater than the cobalt content of the composition at positions 1005 and 1006, and likewise, the cobalt content of the composition at position 1005 can be greater than the cobalt content of the composition at position 1006. It will be appreciated that other catalyst materials besides cobalt can be employed, and can exhibit the features noted in the foregoing.

In certain embodiments, the jacket 1003 can be formed to have layered regions 1008-1010 wherein the compositions differ from each in a greater manner than the content of one chemical species. For example, the layered regions 1008-1010 can differ from each other in that one of the layered regions 1008-1010 can have an entirely different composition than another one of the layered regions 1008-1010. In particular, the jacket 1003 can be constructed such that the layered region 1010 can include a polycrystalline material, such as polycrystalline diamond, wherein the one of the layered regions 1008 or 1009 can be formed of a completely different composition, such as tungsten carbide.

Moreover, it will be appreciated, that the layered regions 1008-1010 can have a distinction in microstructure as compared to each other. For example, the layered regions 1008-1010 can differ from each other on the basis of average grains size, grain size distribution, grade of material, shape of the grains, and a combination thereof. In one particular embodiment, the layered region 1010 can be formed of a material (e.g., tungsten carbide) having an average grain size that is less than the average grains size of the material, which may be the same or different, within the layered region 1009.

It will be appreciated that while the jacket 1003 is illustrated as having discrete layered regions 1008-1010, such radially varying composition can also be achieved through a gradient structure, which may not utilize discrete layered regions within the jacket. The difference between forming a jacket with discrete layered regions having discrete interfaces and a jacket having a gradient structure, wherein the discrete interfaces may not be identifiable, can be achieved through different forming processes, which will be described in more detail herein.

The layered regions 1008-1010 are illustrated as having substantially the same thicknesses, as measured in a direction perpendicular to the longitudinal axis between the respective interfaces separating the layered regions 1008-1010. In certain instances, the layered regions 1008-1010 may not necessarily have the same thickness as compared to each other. Moreover, the layered regions 1008-1010 can have relatively parallel structures, such that they extend along the axial direction 308, and may not necessarily define flanges or similar structures as provided in other components of the cutting element 1000.

According to a particular embodiment, the jacket 1003 can include an outermost layer (e.g., layered region 1010) comprising a first composition, such as tungsten carbide, and the layered region 1009 abutting the outermost layer can have a second, different composition as compared to the first composition. In particular, the second composition of layered region 1009 can be a superabrasive material, such as polycrystalline diamond, cubic boron nitride, and a combination thereof. Other embodiments herein may utilize a combination of tungsten carbide overlying layers or regions of superabrasive material, such that the superabrasive layer acts to further limit effects of erosion. Such configurations of layered regions comprising alternating compositions of superabrasive material and cermet (e.g., tungsten carbide) may serve to improve the life of the cutting element and limit erosion.

FIG. 10B includes a cross-sectional illustration of a cutting element according to an embodiment. The cutting element 1020 can include those components described herein, notably a cutter body 1050 including a substrate 301 and a superabrasive layer 302 overlying the upper surface 307 of the substrate 301. The substrate 301 can further include a jacket 1023 having an inner surface 310 overlying, and in particular, abutting the side surface 305 of the substrate 301. The jacket 1023 can further include an upper surface 1002 that is abutting the rear surface 316 of the superabrasive layer 302. Notably, according to the illustrated embodiment, the jacket 1023 can be formed such that there may not necessarily be a flange overlying the side surface 306 of the superabrasive layer 302, however, it will be appreciated that such configurations can be used.

The jacket 1023 can have an axially varying composition that can be enabled by the formation of layered regions 1027, 1028, and 1029 that are axially spaced apart from each other and define distinct axial regions within the body of the jacket 1023. According to one embodiment, each of the layered regions 1027-1029 can represent regions within the jacket having compositions that can be different from each other. In particular, the layered regions 1027-1029 can exhibit differences in the composition similar to the layered regions 1008-1010 of the embodiment of FIG. 10A. Moreover, the layered regions 1027-1029 can have the same characteristics (e.g., differences in microstructure) as described in accordance with the embodiment of FIG. 10A.

For example, the position 1024 within the layered region 1027 is axially spaced apart from the position 1025 within the layered region 1028, and particularly, the position 1024 can have a composition that is different from the composition of the position 1025. Moreover, the position 1025 within the layered region 1028 is axially spaced apart from the position 1026 within the layered region 1029, and particularly, the position 1025 can have a composition that is different from the composition of the position 1026. Likewise, the positions 1024 and 1026, which are axially spaced apart from each other, can have a difference in composition. The layered regions 1027-1029 can have compositions wherein the content of at least one species is different as compared to the content of the same species within any of the other layered regions 1027-1029. Additionally, the layered regions 1027-1029 can have a composition, wherein at least one chemical species is present within one of the layered regions and can be absent from one of the other layered regions 1027-1029. Furthermore, it will be appreciated that while the jacket 1023 is illustrated as having three layered regions, more or less layered regions can be used to construct the jacket 1023.

As illustrated, the jacket 1023 can have layered regions 1027-1029 that are axially spaced apart from each other and can be separated by discrete interfaces, such that the layered regions 1027 and 1028 can be separated at an interface 1021 that can extend generally perpendicular to the longitudinal axis 308 of the cutter body 1050. Moreover, the layered regions 1028 and 1029 can be separated at an interface 1022 that can extend generally perpendicular to the longitudinal axis 308 of the cutter body 1050.

Notably, the layered regions 1027-1029 can have a difference in chemical composition as compared to each other. For example, according to one embodiment, the composition within the layered region 1027 can have an average cobalt content that is significantly different than the average cobalt content of the composition within the layered region 1028 and/or 1029. In one particular embodiment, the jacket 1023 comprises an axially varying cobalt composition, wherein the average cobalt content decreases as axial position changes moving in a direction parallel to the longitudinal axis 308 from the rear surface 314 to the upper surface 1002 through the body of the jacket 1023. As such, the composition at position 1024 can have a cobalt content that is less than the cobalt content of the composition at position 1025 and/or position 1026.

According to an alternative embodiment, the layered region 1027 can be segmented axially, such that it includes an upper region defining the exterior surface of the jacket 1032 and extending for approximately half of the thickness radially into the interior of the jacket 1032. The layered region 1027 can further include a lower region abutting the substrate 301 and defining an interior surface of the jacket 1032 and abutting the upper region. Accordingly, the layered region 1027 can be segmented into two distinct regions; and upper region and a lower region. The upper region can include a material such as tungsten carbide as noted herein. In contrast, the lower region can include a different material, such as a polycrystalline superabrasive material, and particularly, polycrystalline diamond or cubic boron nitride. The lower region can facilitate limited erosion of the article, particularly behind the superabrasive layer 302. It will be appreciated that the layered region 1027 can be segmented into further layers or have a gradient structure as described herein. Additionally, any of the layered regions 1028 and 1029 can have the same features.

FIG. 10C includes a cross-sectional illustration of a cutting element according to an embodiment. The cutting element 1040 can include those components described herein, notably a cutter body 1050 including a substrate 301 and a superabrasive layer 302 overlying the upper surface 307 of the substrate 301. The substrate 301 can further include a jacket 1041 having an inner surface 310 overlying, and in particular, abutting the side surface 305 of the substrate 301. The jacket 1041 can further include an upper surface 1002 that is abutting the rear surface 316 of the superabrasive layer 302. Notably, according to the illustrated embodiment, the jacket 1041 can be formed such that there may not necessarily be a flange overlying the side surface 306 of the superabrasive layer 302, however, it will be appreciated that such configurations can be used.

The jacket 1041 can have a combination of an axially varying and a radially varying composition that can be enabled by the formation of layered regions 1045, 1046, and 1047, which are curvilinear shaped regions. Each of the layered regions 1045-1047 can have portions that are axially spaced apart from other portions of the layered regions 1045-1047. Stated another way, for a particular radial position within the body of the jacket 1041, traveling along a linear path at the same radial position parallel to the longitudinal axis 308, the composition of the jacket 1041 can change with change in axial position along the length of the jacket 1041 through the layered regions 1045-1047. Likewise, portions of each of the layered regions 1045-1047 can be radially spaced apart from other portion of the layered regions 1045-1047. That is for a particular axial position along the length of the jacket 1041, traveling along a linear path at the same axial position perpendicular to the longitudinal axis 308, the composition of the jacket 1041 can change with change in radial position along the thickness of the jacket 1041 through the layered regions 1045-1047.

According to one embodiment, each of the layered regions 1027-1029 can represent regions within the jacket 1041 having compositions that can be different from each other. In particular, the layered regions 1027-1029 can exhibit differences in the composition similar to the layered regions 1008-1010 of the embodiment of FIG. 10A. Moreover, the layered regions 1027-1029 can have the same characteristics (e.g., differences in microstructure) as described in accordance with the embodiment of FIG. 10A.

For example, the position 1042 within the layered region 1045 is axially and radially spaced apart from the position 1043 within the layered region 1046, and particularly, the position 1042 can have a composition that is different from the composition of the position 1043. Moreover, the position 1043 within the layered region 1046 is axially and radially spaced apart from the position 1044 within the layered region 1047, and particularly, the position 1043 can have a composition that is different from the composition of the position 1044. Likewise, the positions 1042 and 1044, which are axially and radially spaced apart from each other, can have a difference in composition. The layered regions 1045-1047 can have compositions wherein the content of at least one species is different as compared to the content of the same species within any of the other layered regions 1045-1047. Additionally, the layered regions 1045-1047 can have a composition, wherein at least one chemical species is present within one of the layered regions and can be absent from one of the other layered regions 1045-1047. Furthermore, it will be appreciated that while the jacket 1041 is illustrated as having three layered regions, more or less layered regions can be used to construct the jacket 1041.

According to one embodiment, the cutting element 1040 is formed such that the layered region 1047 includes a tungsten carbide material and that can have a different amount of catalyst material as compared to the compositions within the layered regions 1045 and 1046. In particular, the composition within the layered region 1047 is formed such that the cobalt content is less than the cobalt content of the compositions within the layered region 1045 and/or layered region 1046.

In another embodiment, the layered region 1047 can be formed of a material having an entirely different composition as compared to the layered region 1045 and/or the layered region 1046. For example, in one embodiment, the layered region 1047 can be made of a polycrystalline material, such as polycrystalline diamond, while the layered region 1045 and/or the layered region 1046 can be made of a tungsten carbide material.

FIGS. 11A-11C include cross-sectional illustrations of cutting elements employing ring members. In particular, the cutting elements combine the ring member feature with jackets, and particularly, jackets having varying compositions. FIG. 11A includes a cross-sectional illustration of a cutting element according to an embodiment. The cutting element 1100 can include the components described herein, including a substrate 301 and a superabrasive layer 302 overlying the upper surface 307 of the substrate 301. The substrate 301 can further include a jacket 1003 having an inner surface 310 overlying, and in particular, abutting the side surface 305 of the substrate 301. The jacket 1003 can further include an upper surface 1002 that is abutting the rear surface 316 of the superabrasive layer 302. Notably, the jacket 1003 can be formed such that there may not necessarily be a flange overlying the side surface 306 of the superabrasive layer 302, however, it will be appreciated that such configurations can be used.

The jacket 1003 can have a radially varying and/or an axially varying composition having the features described in other embodiments herein. In particular, the jacket 1003 can have layered regions 1008, 1009, and 1010 that are radially spaced apart from each other and extend generally parallel to the longitudinal axis 308 of the cutter body 1050. Each of the layered regions 1008-1010 can represent regions within the jacket having compositions that can be different from each other. The layered regions 1008-1010 can have compositions wherein the content of at least one species is different as compared to the content of the same species within any of the other layered regions 1008-1010. Additionally, the layered regions 1008-1010 can have a composition, wherein at least one chemical species (e.g., a catalyst material) is present within one of the layered regions 1008-1010 and can be absent from one of the other layered regions 1008-1010. Notably, the jacket 1003 can have a radially varying composition, such that the content of a catalyst material, such as cobalt, within the layered regions 1008-1010 are different compared to each other.

In certain embodiments, the jacket 1003 can be formed to have layered regions 1008-1010 wherein the compositions differ from each in a greater manner than the content of one chemical species. For example, the layered regions 1008-1010 can differ from each other in that one of the layered regions 1008-1010 can have an entirely different composition than another one of the layered regions 1008-1010. In particular, the jacket 1003 can be constructed such that the layered region 1010 can include a polycrystalline material, such as polycrystalline diamond, wherein the one of the layered regions 1008 or 1009 can be formed of a completely different composition, such as tungsten carbide. In still other cutting elements, the jacket 1003 can include an outermost layer (e.g., layered region 1010) comprising a first composition, such as tungsten carbide, and the layered region 1009 abutting the outermost layer can have a second, different composition as compared to the first composition. In particular, the second composition of layered region 1009 can be a superabrasive material, such as polycrystalline diamond, cubic boron nitride, and a combination thereof. Other embodiments herein may utilize a combination of tungsten carbide overlying layers or regions of superabrasive material, such that the superabrasive layer acts to further limit effects of erosion.

Moreover, it will be appreciated, that the layered regions 1008-1010 can have a distinction in microstructure as compared to each other. Alternatively, while the jacket 1003 is illustrated as having discrete layered regions 1008-1010, such radially varying composition can also be achieved through a gradient structure, which may not utilize discrete layered regions within the jacket. The difference between forming a jacket with discrete layered regions having discrete interfaces and a jacket having a gradient structure, wherein the discrete interfaces may not be identifiable, can be achieved through different forming processes, which will be described in more detail herein.

The cutting element 1100 further includes a ring member 1101 disposed between the superabrasive layer 302 and the substrate 301. The ring member 1101 can offer additional erosion resistance for the cutting element 1100, particularly in a location directly behind the superabrasive layer 302. The ring member 1101 can be abutting the rear surface 316 of the superabrasive layer 302. Additionally, the ring member 1101 can be abutting a surface of the substrate 301, and particularly, a peripheral side surface 305 of the substrate 301. Moreover, the ring member 1101 can be positioned between the substrate 301 and a layered region 1010 of the jacket 1003, such that a portion of the jacket is overlying the ring member 1101. Notably, the ring member 1101 can be positioned within the cutting element 1100 such that an exterior surface 1102 of the ring member is covered by a portion of the jacket 1003. The ring member 1101 can extend around at least a fraction of the peripheral side surface 305 of the substrate 301, and may extend peripherally along the entire peripheral length of the side surface 305 (e.g., through 360 degrees). Additionally, the ring member 1101 can extend for a fraction of the total length of the cutting element 1100 along the longitudinal axis 308. Still, in other embodiments, the ring member 1101 can extend for the full length of the cutting element 1100.

According to a particular embodiment, the ring member 1101 can include a polycrystalline material. Certain ring members can include a superabrasive material, such as diamond and/or cubic boron nitride. In one embodiment, the ring member 1101 can consist essentially of polycrystalline diamond. In another instance, the ring member 1101 can consist essentially of cubic boron nitride.

The ring member may act as a stop layer for erosion during use of the cutting element 1100, since the ring member 1101 can be made of material having a greater erosion resistance than the jacket 1003. Moreover, the ring member 1101 may facilitate releasable assembly of the jacket 1003, such that after sufficient wear of the jacket 1003 and upon initiation of wear of the ring member 1101, the jacket 1003 can be removed from the substrate and replaced with a new jacket.

It will be appreciated that while the ring member 1101 is illustrated as having a rectangular cross-sectional shape, other shapes can be utilized. For example, the ring member 1101 can include a host of other polygonal cross-sectional shapes, including for example, circular, elliptical, triangular, pentagonal, hexagonal, and the like. Certain cutting elements can employ a ring member 1101 having an irregular shape. Alternative ring members 1101 can have certain protrusions, gaps, recesses, and the like.

The ring member 1101 may have a shape that aids fitting and attachment between the jacket 1003 and the ring member 1101. For example, particularly in the context of releasable and replaceable jackets, the jacket 1003 and the ring member 1101 can be attached by a snap-fit connection, interference-fit connection, complementary-shaped engagement structure (e.g., tongue-in-groove). In other instances, the ring member 1101 and the jacket 1003 can be mechanically bonded to each other, such as through a high temperature bond, such as a brazing process.

FIG. 11B includes a cross-sectional illustration of a cutting element according to an embodiment. The cutting element 1120 can include the components described herein, notably a cutter body 1050 including a substrate 301 and a superabrasive layer 302 overlying the upper surface 307 of the substrate 301. The substrate 301 can further include a jacket 1003 having an inner surface 310 overlying, and in particular, abutting the side surface 305 of the substrate 301. The jacket 1003 can further include an upper surface 1002 that is abutting the rear surface 316 of the superabrasive layer 302. Notably, according to the illustrated embodiment, the jacket 1003 can be formed such that there may not necessarily be a flange overlying the side surface 306 of the superabrasive layer 302, however, it will be appreciated that such configurations can be used.

The cutting element 1120 further includes a ring member 1101 disposed between the superabrasive layer 302 and the substrate 301. Notably, unlike the embodiment of FIG. 11A, the ring member 1101 can be disposed within a recess of the substrate 301, such that it is seated within an interior space of the substrate 301 body. The ring member 1101 can have any of the features noted in other embodiments.

FIG. 11C includes a cross-sectional illustration of a cutting element according to an embodiment. The cutting element 1140 can include the components described herein, notably a cutter body 1050 including a substrate 301 and a superabrasive layer 302 overlying the upper surface 307 of the substrate 301. The substrate 301 can further include a jacket 1003 having an inner surface 310 overlying, and in particular, abutting the side surface 305 of the substrate 301. The jacket 1003 can further include an upper surface 1002 that is abutting a portion of the rear surface 316 of the superabrasive layer 302. In particular designs, the jacket 1003 can be formed to have a flange 348 that extends along a portion of the superabrasive layer 302. That is, the flange 348 can extend along and overlie at least a portion of the side surface 306 of the superabrasive layer 302. Notably, according to the illustrated embodiment, the jacket 1003 can be formed such that there may not necessarily be a flange overlying the side surface 306 of the superabrasive layer 302, however, it will be appreciated that such configurations can be used.

The cutting element 1120 further includes a ring member 1101 disposed between the superabrasive layer 302 and the substrate 301. Notably, unlike the embodiment of FIG. 11A, the ring member 1101 can be disposed within a recess of the substrate 301, such that it is seated within an interior space of the substrate 301 body. Still, a portion of the ring member 1101 extends radially from the recess within the substrate 301 and is disposed within a recess of the jacket 1003. In particular, the exterior surface 1102 of the ring member 1101 can be flush and parallel with the side surface 306 of the superabrasive layer 302. The ring member 1101 can have any of the features noted in other embodiments.

The cutting elements herein may be formed by particular methods such that the components are properly oriented with respect to each other and forces between components are applied as described herein. In accordance with an embodiment, one method of forming includes forming the cutter body comprising the substrate and superabrasive layer as illustrated in embodiments herein. One particular method of forming the cutter body can include a high pressure high temperature (HP/HT) process.

In a HP/HT process, substrate material is loaded into a HP/HT cell with the appropriate orientation and amount of diamond crystal material, typically of a size of 100 microns or less. Furthermore, a metal catalyst powder can be added to the HP/HT cell, which can be provided in the substrate or intermixed with the diamond crystal material. The loaded HP/HT cell is then placed in a process chamber, and subject to high temperatures (typically 1450-1600° C.) and high pressures (typically 50-70 kilobar), wherein the diamond crystals, stimulated by the catalytic effect of the metal catalyst powder, bond to each other and to the substrate material to form a PDC product. It will be appreciated that the PDC product can be further processed to form a thermally stable polycrystalline diamond material (commonly referred to as “TSP”) by leaching out the metal in the diamond layer. Alternatively, silicon, which possesses a coefficient of thermal expansion similar to that of diamond, may be used to bond diamond particles to produce a Si-bonded TSP. TSPs are capable of enduring higher temperatures (on the order of 1200° C.) in comparison to normal PDCs.

The process of forming the cutting elements herein may further include a process of forming a jacket having the dimensions described herein and particularly a central opening for engagement of the cutter body therein. Various forming methods may be undertaken to form the jacket. For example, a one-step process can be utilized to form certain cutting elements of the embodiments herein. A one-step forming process can include the formation of the jacket in an HP/HT process, and particularly forming the cutter body and jacket in the same high pressure high temperature process. In certain instances, the formation of the cutter body and the jacket can be completed simultaneously, such that they are formed in the same chamber at the same time. Such a process may require a special HP/HT cell capable of accommodating both components. The result of the one-step forming process is the formation of a cutting element employing a jacket, wherein the cutter body and jacket are an integrally bonded, monolithic article.

In order to achieve certain characteristics of the embodiments herein, such as a jacket having radially varying and/or axially varying compositions, certain processing steps may be completed before the HP/HT forming steps to fabricate a pre-formed jacket article. For example, a pre-formed jacket article can be formed before the final HP/HT processing such that it includes a plurality of discrete layers, wherein each of the layers contains a particular composition and/or microstructure, such that the final-formed cutting element includes a jacket having an axially varying and/or radially varying composition. Suitable processes for forming a pre-formed jacket article can include pressing, molding, casting, forging, heat-treatment (e.g., sintering) and a combination thereof. The pre-formed jacket may not necessarily be a completely sintered object, and may be a green article, which is an unfinished and unsintered article that may have undergone some heat-treatment to provide strength to the article for handling.

In one particular instance, the pre-formed jacket article can be formed of a plurality of layers, wherein each of the layers are pre-formed individually and then combined together to form the assembled pre-formed jacket. For example, a first layered region can be formed having a particular composition and microstructure, such as through processes that can include molding, pressing, forging, heat-treatment, and a combination thereof. A second layered region can be formed from the same or different composition and microstructure and formed through similar processing. Notably, the first and second layered regions can be shaped in a manner such that they can be combined to form the pre-formed jacket. More layered regions can be formed as needed, and upon completion of the desired number of pre-formed layered regions, the layered regions can be combined and adhered to each other. The layered regions can be adhered through use of a bonding compound, heat treatment, or a combination thereof.

Alternatively, the pre-formed jacket can be formed by a series of successive molding, casting, pressing operations or a combination thereof. The successive forming process can be used to form a series of successive layered regions, wherein in each successive operation, the desired raw materials are selected to form a particular layered region within the pre-formed jacket.

In accordance with other embodiments, depending upon the material of the jacket selected, the jacket may be formed through a different method than the HP/HT process. In such embodiments, the jacket and cutter body can be formed into a cutting element via a two-step forming process, since the joining of the cutter body and jacket may not necessarily be completed in a single process (i.e., HP/HT process). The jacket can be formed by methods including machining, casting, molding, pressing, forging, sintering, and a combination thereof.

In the two-step forming process, after individually forming the cutter body (i.e., superabrasive layer and substrate) and the jacket, the cutter body and jacket may be joined together. As described herein, the cutter body and the jacket can be joined using certain types of connection mechanisms. In certain instances the jacket can be releasably affixed to the cutter body, such that the jacket is a replaceable member and can be disposed of after sufficient wear. In other designs, the jacket is fixably attached to the cutter body, and the connection between the cutter body and the jacket is permanent.

It will further be appreciated that in some processes, a bonding material may be placed at the interface between the jacket and the cutter body to facilitate joining the two components. Suitable bonding materials may be inorganic or organic materials. For example, the bonding material can be a braze material incorporating a metal or metal alloy material. Metal materials of particular use may include metal elements including for example, nickel, iron, manganese, chromium, tantalum, vanadium, titanium, cobalt, tungsten, and a combination thereof and a combination thereof. Notably, super-alloy metals as described herein can also be employed.

It is further contemplated that a mechanical force may be applied to the jacket, cutter body, or both to affect the fitting of the cutter body within the central opening of the jacket. In one particular instance, a force can be applied to the jacket to increase the inner diameter of the central opening to allow the cutter body to fit within the jacket. As such, in particular instances, the cutter body may be extruded into the jacket, such that a mechanical urging force is applied to the substrate to urge the cutter body into the central opening of the jacket, and thereby creating a cutting element wherein the jacket exerts forces (e.g., radial and axial forces) on the cutter body.

In other processes, a press fitting operation can be used to fit the components (i.e., the jacket and the cutter body) together. Press fitting operations can utilize the application of force on the cutter body and/or jacket to affect fitting of the jacket and cutter body together in a manner that the jacket exerts at least a radially compressive force on the cutter body. In particular instances, the press fitting operation can include the formation of a jacket having a central opening designed to allow the cutter body to fit within the central opening During the press fitting operation, the cutter body can be forced into the central opening of the jacket, such that the jacket is forced to expand and consequently, the jacket also applies opposite forces to the cutter body. In particular instances, it may be particularly suitable to introduce the cutter body into the jacket such that the superabrasive layer is first introduced into the central opening. The cutter body is axially displaced through force within the central opening until the proper fit is obtained and the cutter body is properly seated within the jacket. It will be appreciated that chamfered surfaces on the rear of the jacket or on the superabrasive layer or both may aid the initiation of the fitting operation.

Additionally, certain two-step forming processes may employ a temperature differential for fitting of the cutter body within the central opening of the jacket. The process of creating a temperature differential may include increasing the temperature of the jacket, such as by heating the jacket to a temperature greater than a temperature of the cutter body. Such a process may facilitate an increase in the dimensions of the jacket, such that the diameter of the central opening is increased sufficiently for fitting of the cutter body within the jacket. As such, the dimensions of the jacket may initially be created such that the cutter body may not necessarily fit within the central opening of the jacket. However, after providing a temperature differential between the two components, the cutter body and jacket can be combined such that the cutter body fits within the opening of the jacket. It will be appreciated that after fitting the components together, the temperature differential may be removed to affix the components to each other. A temperature differential may also be achieved by cooling the components, particularly the cutter body, such that the dimensions of the cutter body contract (i.e., are reduced) to a suitable degree to facilitate fitting of the components together.

After fitting the cutter body within the central opening of the jacket, a radially compressive force can be applied to the jacket and cutter body to physically reduce the size of the jacket and compress the jacket. Compression of the jacket can facilitate the creation of a frictional bond between the two components and the exertion of a radially compressive force on the cutter body by the jacket. It will be appreciated that certain mechanical features at the interface of the jacket and cutter body, particularly the substrate, may be utilized to facilitate locking engagement and maintaining the compressive state of the jacket.

Additionally, components herein may have distinct mechanical performance based on differences in microstructure. For example, the jacket can be formed of a cemented tungsten carbide material formed from a feed material that is distinct from the tungsten carbide feed material used to form the substrate. The feed material can be varied based on parameters such as size distribution of the grains, quality of the grains, and aspect ratio of the grains to affect certain mechanical properties.

While reference above is made to the differences in properties between the jacket and the substrate, such discussion is illustrative and it will be appreciated that such these differences may exists between other components based on a difference in composition and feed material. Particularly, these differences can exist between the intermediate layer and the substrate, and/or the intermediate layer and the jacket.

The cutting elements herein demonstrate a departure from the state-of-the-art. While cutter designs have been disclosed in the past to mitigate problems associated with mechanical strain, temperature-induced strain, and wear, typically the changes in cutter design have been directed to changing the configuration of the cutter table and/or substrate and the interface between these two components. By contrast, the embodiments herein are directed to cutting elements incorporating multiple components employing a cutter body, a jacket, a collar, multiple chamfers and/or radiused edges, compositionally graded jackets, and other features for improved performance. Embodiments herein further include a combination of features directed to the orientation between the components, different structures of the components (e.g., layered structures), various materials for use in the components, particular surface features of the components, and certain means of affixing the components to each other. Moreover, the cutting elements of the embodiments herein can be formed through particular forming methods not previously utilized in the art, which facilitate the features of the cutting elements herein.

The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true scope of the present invention. Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.

The Abstract of the Disclosure is provided to comply with Patent Law and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing, various features may be grouped together or described in a single embodiment for the purpose of streamlining the disclosure. This disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may be directed to less than all features of any of the disclosed embodiments. Thus, the following claims are incorporated into the description, with each claim standing on its own as defining separately claimed subject matter. 

1. A cutting element comprising: a substrate having an upper surface, a rear surface spaced apart from the upper surface, and a side surface connected to the rear surface and upper surface; a superabrasive layer comprising a rear surface, an upper surface, and a side surface connected to and extending between the rear surface and upper surface, wherein the rear surface of the superabrasive layer overlies the upper surface of the substrate; and a jacket overlying the side surface of the substrate and abutting a portion of the rear surface of the superabrasive layer, wherein the jacket comprises a flange extending along a portion of the side surface of the superabrasive layer.
 2. (canceled)
 3. (canceled)
 4. The cutting element of claim 1, wherein the jacket comprises an average thickness as measured in a radial direction of not greater than about 5 mm.
 5. (canceled)
 6. (canceled)
 7. The cutting element of claim 4, wherein the jacket comprises an average thickness within a range between about 0.1 mm and about 5 mm.
 8. (canceled)
 9. (canceled)
 10. The cutting element of claim 1, wherein the jacket comprises a radially varying thickness.
 11. The cutting element of claim 1, wherein the jacket comprises an axially varying thickness.
 12. (canceled)
 13. (canceled)
 14. The cutting element of claim 1, wherein the jacket comprises an inorganic material selected from the group of materials consisting of metal, ceramic, cermet, and a combination thereof.
 15. (canceled)
 16. The cutting element of claim 15, wherein the jacket comprises a metal element selected from the group of elements consisting of titanium, chromium, nickel, tungsten, cobalt, iron, molybdenum, vanadium, and a combination thereof.
 17. (canceled)
 18. The cutting element of claim 1, wherein the jacket comprises a contoured inner surface for complementary engagement with a contoured region along the side surface of the substrate.
 19. (canceled)
 20. The cutting element of claim 1, wherein the jacket is mechanically interlocked with the substrate. 21-28. (canceled)
 29. A cutting element comprising: a cutter body comprising: a substrate having an upper surface, a rear surface spaced apart from the upper surface, and a side surface connected to the rear surface and upper surface; a superabrasive layer comprising a rear surface overlying the upper surface of the substrate at a substrate/superabrasive layer interface; and a jacket comprising an erosion-resistant material overlying a periphery of the substrate/superabrasive layer interface at a side surface of the substrate, wherein the jacket extends for a fraction of a total length of the cutter body.
 30. The cutting element of claim 29, wherein the jacket comprises a collar extending peripherally around the side surface of the substrate and around a side surface of the superabrasive layer. 31-37. (canceled)
 38. The cutting element of claim 29, wherein the jacket is releasably attached to the cutter body.
 39. The cutting element of claim 29, wherein the jacket is fixably attached to the cutter body. 40-56. (canceled)
 57. The cutting element of claim 29, wherein the jacket comprises an axially varying composition, wherein the composition of the jacket at a first axial position is different than a composition of the jacket at a second axial position, the first and second axial positions spaced apart from each other along a length of the jacket.
 58. The cutting element of claim 57, wherein the axially varying composition comprises a gradient of cobalt content along the length of the jacket, wherein the cobalt content of the jacket at the first axial position is different than a cobalt content of the jacket at the second axial position.
 59. The cutting element of claim 58, wherein the first axial position is closer to the superabrasive layer than the second axial position, and wherein the cobalt content of the jacket at the first axial position is less than the cobalt content of the jacket at the second axial position.
 60. The cutting element of claim 29, wherein the jacket comprises a radially varying composition, wherein the composition of the jacket at a first radial position is different than a composition of the jacket at a second radial position, the first and second radial positions spaced apart from each other along a thickness of the jacket.
 61. The cutting element of claim 60, wherein the radial varying composition comprises a gradient of cobalt content along the thickness of the jacket, wherein the cobalt content of the jacket at the first radial position is different than a cobalt content of the jacket at the second radial position.
 62. The cutting element of claim 61, wherein the first radial position is closer to the substrate than the second radial position, and wherein the cobalt content of the jacket at the first radial position is greater than the cobalt content of the jacket at the second radial position. 63-70. (canceled)
 71. A cutting element comprising: a substrate having an upper surface; a superabrasive layer comprising a rear surface overlying the upper surface of the substrate at a substrate/superabrasive layer interface; and a jacket overlying a periphery of the substrate/superabrasive layer interface, wherein the jacket comprises a coating including an erosion-resistant material. 72-116. (canceled) 